This paper deals with analysis of thermal characteristic and power loss of induction motors for machine tool spindle considering load condition.
A trend in high-speed/high-performance machining technology involves targeting a spindle that can perform high-speed and high-power machining operations. For such applications, the spindle motor should be able to provide the power needed for cutting even when running at high rotational speeds.Because the specified applications incur a wide variety of cutting load conditions, the machine efficiency and temperature rise in the motor are of great interest to machine tool manufacturers.
Induction motors are the most common type of motors used in machine tools. High-performance induction motors with variable-voltage, variable-frequency (VVVF) inverters are often applied to machine tool spindles that operate at lower speeds and lower output powers than the motor’s rated values
Meanwhile, the temperature rise in an induction motor critically affects the failure rate and service life. In particular, the temperature rise of the stator and rotor resulting from a significant stator core loss, copper loss, or rotor loss, as caused by variations in the current, could adversely affect the torque characteristics and durability. Moreover, the temperature rise affects the fabrication quality and cutting error in ultra-precision rotational machine tools. To reduce the fabrication and cutting errors caused by thermal strain in a machine tool spindle, deals with the following study.
Firstly, paper present design theory the characteristics of the induction motor. From the result, torque-speed characteristic curve in Catalog is similar to induction motor by design. The inverse design of general induction motors for machine tool spindle has been performed by design principles. This paper analyzed the equivalent circuit of the induction motor. Characteristics of induction motors considering VVVF inverter were analyzed.
Secondly, paper is adopted the experimental model that 0.4kW class general induction motor. This paper presents an investigation of power loss distribution in an induction motor for machine tool spindles considering the effect of loading. This paper employed the design of experiment (DOE) and response surface methodology (RSM) techniques for power loss analysis. To develop a second-order fitted model of the power loss distribution, the central composite design (CCD) technique was used. CCD is frequently used for fitting a second-order response model. By using commercial finite element analysis software (Ansys Maxwell 2D v.16), the steady-state power losses are calculated in the constant-torque region of the induction motor.
Finally, modeling for thermal analysis was performed using Motor-CAD v.7.2.5 software (Motor Design Ltd.). This paper analyzed the main parameters and thermal resistance. The transient thermal characteristics of the induction motor are calculated by applying the equivalent thermal resistance model from Motor-CAD v.7.2.5 software. And to validate the theoretical characteristic analysis results, temperature measurements were performed using a commercial induction motor.
This Paper also implemented a measurement test setup and confirmed that the experimental results were in good agreement with the results of the proposed simulation.